The separatory funnel is clamped near the top and the small tube at the bottom often breaks when the funnel drops off from the clamps. There's no replacement for the tube and the whole funnel needs to be replaced which costs around $25-$120. Printing this protective gear will save the costs incurred to replace the broken funnels.

This equipment is modelled in FreeCAD and the sizes can be easily changed by editing the contraints. The STL files can be directly used to 3D print the equipment for a 250 mL separatory funnel. Recommended Print Settings->0.25mm layer height, 15-30% infill, wall count - 3 minimum.

After prinitng, minor filing might be required based on the accuracy of your printer. Closer tolerances are used to snap fit the parts to the funnel. This makes sure that the parts can be only press-fitted and can't come out when the funnel drops on the floor.

The approximate cost of prinitng this equipment shouldn't be more than a $1. The material that was used by the designer was PLA 1.75mm which costed $20 for a kilogram.